This application incorporates by reference Taiwanese application Serial No. 89111197, Filed Jun. 8, 2000.
1. Field of the Invention
The invention relates in general to a transformer bobbin, and more particularly to a transformer bobbin for preventing the coils from a short circuit.
2. Description of the Related Art
The transformer mainly includes a bobbin and a core for transforming the voltage between the low-voltage port and the high-voltage port of the bobbin. The low-voltage port and the high-voltage port of the bobbin are wrapped around by the copper coils, and the core is placed on the middle and the sides of the bobbin, which is able to complete the voltage transformation.
Referring to FIG. 1, which depicts a three-dimensional diagram of a bobbin on the conventional transformer. The bobbin 100 includes a hollow sleeve 102, the partitions 104, 106, 108, and 110, and the pin sets 112 and 114. The core is placed in the hollow part of the hollow sleeve 102 (not shown in FIG. 1), and the outside of the hollow sleeve 102 is wrapped around by the copper coils (not shown in FIG. 1). The partitions 104, 106, 108 and 110 are perpendicular connected to the hollow sleeve 102. The high-voltage port is formed by wrapping the copper coils around the hollow sleeve 102 between the partition 106 and 110. The low-voltage port is formed by wrapping the copper coils around the hollow sleeve 102 between the partition 106 and 104. The spools 120, 122 and 124 represent the space between the partitions 110 and 108, the space between the partitions 108 and 106, the space between the partitions 106 and 104, respectively. Moreover, the partitions 104 and 110 are perpendicular connected to the pin sets 112 and 114, respectively. The pin sets 112 and 114 include a number of pins that are twined round by the starting point and the terminal point of the copper coils.
Referring to FIG. 2A, which depicts a diagram that parts of the copper coils wrap around the bobbin in FIG. 1. Also, referring to FIG. 2B, which depicts a diagram that all of the copper coils wrap around the bobbin in FIG. 1. First, the pin 116 is twined round by the starting point 200 of the copper wire, as shown in FIG. 2A, and then, the hollow sleeve 102 between partitions 108 and 110 is clockwise wrapped around by the copper wire to construct the copper coil 204. In FIG. 2B, through a gap in the partition 108 (not shown in FIG. 2B), the copper wire continuously wraps around the hollow sleeve 102 between partitions 106 and 108. After completing the winding of the copper coil 204, the copper wire passes the side edge of the partition 108, and the terminal point 205 of the copper wire twines round the pin 118.
In order to give a clear description thereinafter, the copper wire segment from the starting point 200 to the winding-started point A is defined as the leading copper wire 206, and all of the copper coil 204 is defined as the coil body 208, wherein the winding-started point A is the point that the copper wire starts to wrap around the hollow sleeve 102.
Referring to FIG. 3A, which depicts a front view of the transformer in FIG. 2B along the X-axis. Also, referring to FIG. 3B, which depicts a lateral view of the transformer in FIG. 2B along the Y-axis. In FIG. 3A, the starting point 200 of the copper wire twins round the pin 116, and then multiple layers of the copper coil 204 wraps around the hollow sleeve 102. Portion of the leading copper wire 206 is lying on the pin set 114, and the other portion is placed on the surface of the partition 110 that is parallel to the YZ-plane. Therefore, the leading copper wire 206 placed on the partition 110 touches the coil body 208 at the interface 302.
In FIG. 3B, each circle represents a copper coil 204 outside of the hollow sleeve 102. Similarly, the starting point 200 of the copper wire twins round the pin 116, and part of the leading copper wire 206 touches the coil body 208 at the interface 302.
Accordingly, it could cause some problems that the leading copper wire 206 touches the coil body 208 at the interface 302. First, the high-voltage port includes spools 102 and 122, and the voltage difference between the starting point 200 and the terminal point of the copper wire is very big, and it can be in the range of 1000 to 1200 voltage. Moreover, the voltage difference between the leading copper wire 206 and the upper layer of the coil body 208, about 500 to 600 voltage, is also big. Therefore, the contact of the leading copper wire 206 and the coil body 208 is able to cause a short circuit if the insulating coating of the copper wire is defective. Second, the copper coil 204 wraps around the bobbin 100 by means of a rotating machine, and the rotational speed is pretty fast. Therefore, the copper coil 204 of the coil body 208 will rub against the leading copper wire 206 during the rotation, and the insulating effect disappears. If so, the transformer is broken and cannot work anymore.
It is therefore an object of the invention to provide a transformer bobbin, which the leading copper wire is isolated from the coil body. It can prevent the short circuit and raise the yield of the transformer.
The invention achieves the above-identified objects by providing a bobbin of a transformer for transforming voltage between a first port and a second port of the bobbin, the first port is wrapped around by a first copper wire and forming a plurality of copper coils of the first port, and the second port is wrapped around by a second copper wire and forming a plurality of copper coils the second port. The bobbin includes a hollow sleeve, a first pin set, a partition, and a second pin set. The hollow sleeve is a hollow polyhedron, wherein the hollow sleeve is wrapped around by the copper coils of the first port and copper coils of the second port. A winding-started point is near a corner of the hollow sleeve. The winding-started point is the point that the first copper wire starts to wrap around the hollow sleeve. The first pin set includes a first pin and a first griding slot, wherein the first pin is for being wrapped around by a starting point of the first copper wire, and the first griding slot is for placing the copper wire segment from the starting point to the winding-started point. The partition is for connecting the hollow sleeve and the first pin set. The second pin set includes a third pin and a fourth pin, wherein the third pin and the fourth pin are wrapped around by the starting point and the terminal point of the second copper wire, wire, respectively. The corner of the hollow sleeve is an intersection point of a top plane the hollow sleeve, a side plane of the hollow sleeve, and the partition.